Happy Birthday Rihanna! Singer Kicks Off 25th Birthday Celebrations in Hawaii [PHOTOS]

Rihanna, who recently launched her first fashion collection at the London Fashion Week, reportedly jetted off to Hawaii to celebrate her 25th birthday.

"Already started celebrating MY birthday!!! Haa #PoItUpPoItUp," she wrote on Instagram, along with a picture of her relaxing near a pool. The Diamonds singer was spotted wearing black Harem pants, a cap, Chanel pumps and also a crop top from her latest River Island range.

"I know you want my cropped knot tank #RIHforRiverIsland," she added.

Rihanna's best friend, Melissa Forde, also posted photos of Rihanna - in a bright yellow bikini paired with bracelets, rings and chains around her neck - smoking a cigarette.

There are rumors her on-again-off-again boyfriend, Chris Brown, is planning to propose to Rihanna at her dinner party, which will be attended by her parents, cousins and friends. According to a report in Hollywood Life, the engagement ring is 10 carats and it cost him around £2.27m ($3.5 million).The report says that Brown even asked her parents for their daughter's hand in marriage and Rihanna's father, Ronald Fenty, approved it.

"Of course they'd have my blessing," the 54-year-old Barbadian told Now magazine, "I would be ecstatic. I like Chris. He's a very old- fashioned kind of guy, with straight-up morals and he's always been very decent to me."

Brown and Rihanna were last spotted publically cosying up at the 55th Grammy Awards.

Meanwhile, leading feminist writer Camille Paglia compared RiRi to Princess Diana in The Sunday Times magazine. Rihanna was more than happy to be compared with the late Princess of Wales.

Click here to take a look at Rihanna for River Island show at the Autumn/Winter 2013 collection during London Fashion Week...

As she turns 25, take a look at the stunning pictures of the singer...